【摘要】 利用高亚洲地区32个Mascon,基于GRACE RL05时变重力场模型频域和空域上的两种计算方法有效分离并提取出高亚洲冰川及其毗邻地区的等效水质量变化,得到2002—2013年期间高亚洲地区更为可靠的Mascon质量变化.高亚洲冰川质量变化的空间特征是:青藏高原内陆地区以正增长为主,边缘地区以负增长为主,在藏东南的最边缘地区冰川质量损失最为严重.天山地区、帕米尔和昆仑山地区、喜马拉雅山和喀喇昆仑山地区、青藏高原内陆地区冰川质量的平均变化趋势分别为-2.8±0.9Gt/a、-3.3±1.5Gt/a、-9.9±2.1Gt/a和5.0±0.8Gt/a,高亚洲冰川质量整体的平均变化趋势为-11.0±2.9Gt/a.印度等北部平原地区地下水平均变化趋势为-35.0±4.2Gt/a,该地区地下水信号泄漏是影响GRACE研究高亚洲冰川质量变化的关键因素,频域法和空域法能有效改正该地区地下水信号泄漏的影响.更多还原

【Abstract】 The High Asia is the largest glacierized region over low-and mid-latitudes.During the last decade,the Gravity Recovery and Climate Experiment(GRACE)satellite mission has provided valuable data for monitoring glacial mass changes in High Asia.The new released GRACE RL05 data is used to estimate the glacial mass changes in High Asia from April 2002 to July 2013.After removing glacial isostatic adjustment(GIA)and hydrological contributions from GRACE RL05 data,the least square fitting in the spectral domain and iteration in the spatial domain are used to separate the equivalent water mass changes in 17 mascons over High Asia and15 mascons over the plains of northern India,and quantify more reliable mass changes in High Asia during the period 2002 to 2013.The impacts of groundwater signal leakage from the plains of northern India on GRACE estimates are discussed in detail based on 17 mascons over High Asia.The equivalent water mass changes in mascons are obtained in the spectral and spatial domain.The equivalent water height changes estimated from spectral and spatial domain show a good agreement in the spatial distribution.The largest equivalent water height change trends of Tianshan,Pamirs and Kunlun shan,Himalaya and Karakorum,Inner Tibet Plateau estimated from spectral and spatial domain are-1.7cm·a-1 and-2.1cm·a-1,-1.5cm·a-1 and-2.0cm·a-1,-10.9cm·a-1 and-16.3cm·a-1,2.2cm·a-1 and 2.6cm ·a-1,respectively.The average glacial mass change trends of Tian Shan,Pamirs and Kunlun Shan,Himalaya and Karakorum,Inner Tibetan Plateau are-2.8±0.9 Gt/a,-3.3±1.5 Gt/a,-9.9±2.1Gt/a,5.0±0.8Gt/a,respectively.The average glacial mass change trend of High Asia is-11.0±2.9Gt/a.The groundwater in the plains of northern India shows obviously mass loss at rate of-35.0±4.2 Gt/a.Without considering the leakage effects from the plains of northern India,the average glacial mass change trends of four sub regions in High Asia are-2.7±1.0Gt/a,-1.5±1.5 Gt/a,-15.7±1.8Gt/a,5.0±0.8 Gt/a,respectively,and average glacial mass change trend of High Asia is-14.9±2.7Gt/a.The spatial pattern of the glacial mass changes in High Asia is dominated by increases in the inland of the Tibetan Plateau,and by decreases at the margin,respectively.And the largest mass loss occurs at the margin of the southeastern Tibetan Plateau.The glacial mass change trends of Tian Shan,Pamirs and Kunlun Shan,Himalaya and Karakorum,Inner Tibetan Plateau are-2.8±0.9Gt/a,-3.3±1.5Gt/a,-9.9±2.1Gt/a,5.0±0.8Gt/a,respectively.The average glacial mass change trend of High Asia is-11.0±2.9Gt/a.The groundwater signal leakage from the plains of northern India is the key factor to study the estimations of the glacial mass changes in High Asia with GRACE data,and have significant impact on estimates in Pamirs and Kunlun Shan,Himalaya and Karakorum.The impact of such leakage can be effectively corrected by the spectral and spatial domain methods.Because GRACE senses the total mass change,the estimations of the glacial mass changes can be affected by various model errors.It is necessary to have a long and continuous measurement of satellite gravity,and combine the satellite gravity data with other space geodesy techniques to understand the mass change mechanism in High Asia.更多还原